1. Technical Field
The present invention relates to a technology for identifying a position, at which an object (hereinafter, referred to as pointing body), such as a finger or a pen, is in contact with a display surface of a liquid crystal device, which displays an image.
2. Related Art
An existing liquid crystal device with a touch panel that uses an electrostatic capacitance method has been proposed. As described in JP-A-5-19233, JP-A-8-44493, JP-A-2000-81610 and JP-T-2003-511799, detection electrodes are formed on a viewing side of the liquid crystal device. The position of the pointing body is identified on the basis of a signal that is obtained by detecting a variation in electrostatic capacitance of each detection electrode.
In the meantime, a parasitic capacitance is formed between the detection electrodes and electrodes or wirings of the liquid crystal device. Thus, when various signals used for displaying an image vary in the liquid crystal device, there is a problem that noise is induced in the detection electrodes. Noise in the detection electrodes causes a decrease in accuracy of position identification of the pointing body.